Christ as Savior is certainly the main objective
Revelation 12 is a bit of an enigma, compared to the other chapters. It appears to paint a broad overview, which is still nice information.
It DOES seem that Satan is freer to do evil during those days.
Perhaps because the Restrainer has stepped out of his way (well, not perhaps). I think absolutely because.
To me, Satan was kicked out of Heaven before the foundation of the Earth. Salvation was certainly planned before then (Lamb slain before the foundation of the Earth).
Satan was already walking the Earth in the Book of Job. Somehow he came in the form of the serpent in the Garden. And Christ refers to him as the prince of this world nearly 2,000 years ago in a present tense.
——>Perhaps because the Restrainer has stepped out of his way
The Restrainer of the Antichrist was PAGAN ROME. All but one of the Early Church Fathers who commented on the subject, agree.
Also look at Romans 13: 3For rulers are not a terror to good works, but to the evil. Wilt thou then not be afraid of the power? do that which is good, and thou shalt have praise of the same:
https://www.biblelightinfo.com/fathers-on-antichrist.htm
Rev 10:7 But in the days of the voice of the seventh angel, when he shall begin to sound, the mystery of God should be finished, as he hath declared to his servants the prophets.